Assessment of the health and antioxidant trade-off in gilthead sea bream ( Sparus aurata L.) fed alternative diets with low levels of contaminants

• Published in: Aquaculture Vol. 296; no. 1; pp. 87 - 95
• Main Authors: Saera-Vila, Alfonso, Benedito-Palos, Laura, Sitjà-Bobadilla, Ariadna, Nácher-Mestre, Jaime, Serrano, Roque, Kaushik, Sadasivam, Pérez-Sánchez, Jaume
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2009; Amsterdam: Elsevier Science; Elsevier; Elsevier Sequoia S.A
• Subjects: Agricultural sciences; Alternative complement pathway; Animal aquaculture; animal health; Animal productions; Animal, plant and microbial ecology; anti-inflammatory activity; antioxidants; Applied ecology; Aquaculture; Aryl hydrocarbon receptors; Biological and medical sciences; bream; Cytochrome P450 1A1; Diet; dietary fat; dioxins; Ecotoxicology, biological effects of pollution; enzyme activity; Enzymes; feed composition; feed contamination; feeds; Fish; fish culture; fish feeding; Fish oil; Fish oils; free radical scavengers; Functional foods & nutraceuticals; Fundamental and applied biological sciences. Psychology; gene expression regulation; General aspects; Glucose regulated protein 75; Glutathione; immunity; Life Sciences; linseed oil; lipid peroxidation; liver; Lysozyme; Marine; marine fish; metabolic detoxification; Metallothionein; omega-3 fatty acids; organochlorine pesticides; palm oils; Peroxidases; phospholipids; Plant proteins; polybrominated diphenyl ethers; polychlorinated biphenyls; polycyclic aromatic hydrocarbons; polyunsaturated fatty acids; rapeseed oil; reactive oxygen species; ROS production; Sciences and technics of fishery; Sparus aurata; Studies; Techniques; toxic substances; transcription (genetics); vegetable oil; Vegetable oils; Vegetal oil; Plant proteins; Cytochrome P450 1A1; Peroxidases; ROS production; Vegetal oil; Aryl hydrocarbon receptors; Fish oil; Alternative complement pathway; Glucose regulated protein 75; Metallothionein; Lysozyme; Glutathione; Biological marker; Vegetable oil; Glucose; Marine environment; Sparus aurata; Pisces; Environment quality; Enzyme; Cytochrome P450; Sea bream; Antioxidant; Metalloproteins; Glycosylases; Ah receptor; Vertebrata; Health status; Diet; Glycosidases; Plant protein; Hydrolases; Contaminant; ARYL HYDROCARBON RECEPTOR; METALLOTHIONEIN; VEGETAL OIL; CYTOCHROME P450 1A1; LYSOZYME; HUILE VEGETALE; FISH OIL; ROS PRODUCTION; ALTERNATIVE COMPLEMENT PATHWAY; GLUCOSE REGULATED PROTEIN 75; DAURADE ROYALE; PEROXIDASE; GLUTATHIONE; PLANT PROTEIN
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/j.aquaculture.2009.07.028

The aim of the present work was to analyze the effect of partial and total replacement of fish oil (FO) by a blend of vegetable oils on the health and antioxidant status of gilthead sea bream ( Sparus aurata L.) fed primarily plant protein-based diets. The study included measurements of feed-borne contaminants, gene expression analyses of detoxifying and antioxidant pathways and measures of antioxidant and innate immune descriptors. Polybrominated diphenyl ethers (PBDEs) were almost undetectable in all diets, and the loading-charges of polychlorinated biphenyls (PCBs), dioxin-like PCBs, organochlorine pesticides (OCs), and polycyclic aromatic hydrocarbons (PAHs) were at trace levels decreasing their concentrations according to the level of FO replacement with vegetable oils (0%, 33%, 66%, and 100%). Hepatic detoxifying pathways were down regulated by FO replacement, and the hepatic transcription of cytochrome P450 1A1 and aryl hydrocarbon receptor 1 was significantly reduced in fish fed the 100% vegetable oil diet. Dietary intervention did not alter the hepatic expression of the recycling glutathione reductase, whereas glutathione peroxidase-1 and phospholipid glutathione peroxidase were either down- or up-regulated by total FO replacement. This suggests that vegetable oils prime the in situ repair of peroxidized phospholipids rather than the increased turnover of membrane phospholipids from the undamaged pool of cytosolic free fatty acids. The hepatic expression of non-enzymatic antioxidants (metallothionein, glucose regulated protein 75) was down regulated in fish fed 66% and 100% vegetable oil diets. Hepatic glutathione levels and total plasma antioxidant capacity were also lowest in fish fed high levels of vegetable oils, but the concurrent increase in the GSH/GSSG ratio was interpreted as an index of reduced oxidative stress. This redox balance agrees with the enhanced respiratory burst of blood leucocytes after phorbol myristate acetate stimulation in fish feed the 100% vegetable oil. Total plasma peroxidases and plasma alternative complement pathway were not affected by dietary treatment, whereas plasma lysozyme was significantly decreased in fish fed the 66% vegetable oil diet. Taken together, the results suggest that the health and the antioxidant status of gilthead sea bream was not damaged by high levels of FO replacement in eco-friendly diets, but both the scavenging and production of reactive oxygen species were modulated in concert by complex and nutritionally mediated readjustments.